It's early May and a taste of summer is here. The sun is shining and Ben and Eve are going for their first swim of the year in a nearby lake. Ben's toe touches the surface of the lake, it tingles from the cold. Carrying two Floating Mattresses and a bag with beachwear Eve comes over to Ben and gently drops everything in the sand. How was the water?, she asks. Great, answers Ben with a not so convincing smile, let's do this!
The floating mattress is created from cylinders and end spheres, except for the pillow part which is designed in Onshape. It's an easy design and is a good first part to create for someone new to Onshape. Below is an example on how you could go about it. Don't expect this to be the best solution…it is just ONE way and an easy introduction for someone completely new to Onshape and perhaps to 3D design in general.
Go to the sign in page and create an account: https://cad.onshape.com/signin
Once you are logged in, find the Create button and create a new document.
Start a new sketch:
Choose sketch plane by clicking a plane:
View normal to sketch plane by right clicking anywhere in the sketch area:
Draw a support rectangle with close to 8x4 mm sides. To set the exact measurements just start typing once you've let go of the mouse button.
Then draw 3 point arches for the sides. To get exact measurements just start typing once the you have drawn the arch and let go of the mouse button. Use a radius of 15 for the the longer sides and 4 for the shorter.
Mark "arched" area and use extrude to give the surface volume:
Change the extrude depth to 2.5 mm:
Time to soften the edges a bit to get the final part. First mark the flat surface area and then choose fillet 1.25:
Then mark the corner edges, press fillet and chose 0.5:
Your floating mattress pillow is done and ready to be exported. Right click Part 1 in your lower left side banner and export:
The floating mattress pillow is done and the rest of the mattress is just made of cylinders with end spheres. I assembled everything in 3D builder, but you could just as well use the assembly tab in Onshape instead once you have drawn all parts.
First print in 1:87 scale failed, the distance between the cylinders was just too tight and the end result looked flat. Therefor I separated them slightly and held them together with a flattened bottom cylinder. That small change worked great and the floating mattress is now an easy print even with PLA filament.
There are a few water drops on the floating mattresses in the picture since the kids tried them in real water…quite cute I can assure you :)
Print with as thin layer height as possible and preferably use some transparent filament for best effect.
Files for download
Floating Mattress at Thingiverse Floating Mattress at Prusa Prints